I have still to make all this PAM/LDAP goodness work with just one click but at least the mechanisms work and I'll get there eventually. The idea is that you can set up a single logon mechanism via the LDAP database, and with that one userID/password combination, a user can get into the email, database and any other system. Next - I've got to make this work also with MySQL, which surprisingly, is harder to do than with Postgres.

One more thing - I've been troubled that with I've had to create a postgres user in order to run my previous installers. There's already a _postgres user built into every Lion and Mountain Lion system and I ought to be using it. So I've finally figured out how to make everything work with that built-in _postgres user. So, if you use this latest 9.2.1 Postgres Installer, you can safely delete the postgres user from your users' list in the Users & Groups Preference Pane, after you've run the installer and upgraded your current Postgres installation to 9.2.1.